Conventionally, two-phase motors driven by a two-phase AC is used in various devices.
Patent Literature 1 discloses a two-phase motor in which 18 rotor magnets are arranged with equal intervals in the circumferential direction, and 12 stator salient poles are also arranged with equal intervals in the circumferential direction. According to this structure, each interval between two adjacent stator salient poles is 3π/2 radians in electrical angle. A coil is wound on each stator salient pole by concentrated winding, and assuming that the stator salient poles are assigned A1, B1, A2, B2, . . . , A6, and B6 in the sequential order of the alignment in the circumferential direction, the coils belonging to A group (A1, A2, . . . , A6) are connected to form an A-phase winding, and the coils belonging to B group (B1, B2, . . . , B6) are connected to form a B-phase winding. As a whole, the windings of the stator salient poles have a two-phase winding structure. The two-phase windings are supplied with two-phase alternating currents.
The two-phase windings applied with the two-phase alternating currents are excited to generate a revolving field in the air gap. In synchronism with this rotating field, the rotor magnet receives an attracting (repulsive) force, so that it continues to rotate at a constant synchronous rotation speed.